Heart failure is a syndrome of profound clinical and public health importance. Heart failure (HF) is estimated to contribute to nearly 1 million hospitalizations and approximately 250,000 deaths annually in the U.S. The number of new cases of HF in the U.S. is estimated to exceed 400,000 annually. Though reliable estimates of the magnitude, incidence, and mortality of HF remain sorely lacking, HF is associated with a grim prognosis. However, little recent data exist, particularly from a community-wide perspective, to determine whether the incidence or survival associated with HF, and the management of this clinical syndrome, has changed over time. This study proposes to examine temporal trends (1995 and 2000) in the incidence rates of HF, its therapeutic management, and changes over time in the hospital and long-term survival of patients with HF from a multi-hospital, population-based perspective. The study will take place in residents of the Worcester (MA) metropolitan area (1990 census 437,000) and will examine changes over time in these and additional outcomes for patients with validated HF during 1995 and 2000. Complimenting the hospital surveillance of HF, newly diagnosed cases of HF occurring in members of the largest HMO in Central Massachusetts during 1995 and 2000 will be identified and monitored over time. The proposed project will build on the investigators' clinical and epidemiological experience and on data collection efforts and methodologies used in the ongoing community-wide study of coronary heart disease in greater Worcester residents. To accomplish the study objectives, the medical records of residents of the Worcester metropolitan area hospitalized with a discharge diagnosis of HF and related diagnostic rubrics will be individually reviewed and validated according to pre-established diagnostic criteria. The use of traditional criteria for HF as well as development of new criteria for the epidemiological study of HF will be an important focus of this observational study. Records for additional hospitalizations and death certificates will be reviewed to examine trends in long-term survival of discharged hospital patients through the year 2005. The results of this study will provide much needed information about the epidemiology of HF from a more generalizable population-based perspective. Information would be provided about the clinical and descriptive epidemiology of this prevalent and disabling condition in men and women and individuals of different age groups. The proposed surveillance system will provide insights and guidance to public health and clinical efforts of HF and in monitoring trends in this newly emerging chronic disease.